Drawing ER Diagrams in SmartDraw - Part 2

Placing the Relationship Symbol

To add a relationship symbol between two entities, first draw the line connecting the two entities. Then, drag a relationship symbol from the ERD library and drop it on the line. (Make sure that Allow Shapes to Link to Lines is turned on under the Arrange menu.)

Dropping a relationship symbol on a line

If you're dropping a relationship symbol on a vertical line, it might not attach correctly. To make sure the symbol retains its original angle of rotation, right-click on the line and select Horizontally under Align Shapes and Text to Line.

Dropping a relationship symbol on a line

Drawing Cardinality and Ordinality Relationships

You can express cardinality and ordinality on an E-R diagram in a number of ways. For a quick look at the different types of notations, click here.

Adding Arrows

You can represent cardinality and ordinality by adding arrowheads to the lines connecting entities. To do so, select a line, go to Arrowheads under the Lines menu, and go to More Styles under Arrowheads. Choose the appropriate arrowhead for the type of relationship you want to illustrate.

Choose the arrowhead that represents the appropriate cardinality and ordinality